PROJECT SUMMARY/ABSTRACT The overall goal of the proposed studies is to examine the facilitators and barriers to oncology clinical trial enrollment of older patients (age > 70) with cancer. This proposal addresses a key scientific priority of the National Institute on Aging to increase inclusion of older adults in oncology clinical studies. This is important because one in four Americans over the age of 70 will be diagnosed with cancer in their lifetime. From 2018 to 2040, cancer incidence is expected to rise 88% for individuals age > 70. However, despite this disproportionate incidence and impact of cancer on older adults, they are severely underrepresented in cancer clinical trials. To identify means of increasing participation of older adults, the proposed research builds on two preliminary studies that highlight key gaps in our understanding of the facilitators and barriers to clinical trial enrollment of older adults with cancer. Although numerous studies have shown that the barriers are multifaceted, arising from a combination of system, physician, patient, and/or caregiver factors, few studies have prospectively examined the facilitators and barriers to oncology clinical trial enrollment from both the patient and physician perspectives, and none have explored the caregiver barriers. To address this gap, the Specific Aims are to: Aim 1. Describe the characteristics of older adults (age > 70) with cancer who do and do not enroll in oncology clinical trials, and determine the reasons for non-enrollment; and Aim 2. Identify the facilitators and barriers to oncology clinical trial enrollment of older adults (age > 70) with cancer from the patient, caregiver, and physician perspectives. In Aim 1, we will perform a secondary data analysis of a national prospective study that used a clinical trial screening tool within the National Cancer Institute Community Oncology Research Program, a consortium of 46 community sites across the US. In Aim 2, we will conduct a prospective study of 40 older patients (age > 70) with cancer at City of Hope and affiliated community sites (20 patients who do enroll and 20 patients who do not enroll in a therapeutic oncology clinical trial). Patients? caregivers and oncologists will also be recruited. Qualitative semi-structured interviews with each stakeholder (patient, caregiver, or oncologist) will be conducted to explore the barriers and facilitators to enrollment. Quantitative data will be collected to determine if facilitators and barriers differ by patient characteristics (i.e., geriatric assessment), caregiver characteristics (i.e., caregiver burden), and oncologist characteristics. This research will have significant impact because it will provide a roadmap for developing and testing strategies to increase participation of older adults in oncology research. Furthermore, these studies will provide a new, substantive departure from current studies by simultaneously assessing the patient, caregiver, and physician perspectives. Finally, the proposed research will provide the mentorship, training, and experience that will successfully launch Dr. Sedrak?s independent career in patient-oriented, geriatric oncology research.